1. Field of the Invention
The present invention relates to an input key to be provided in the input operation device of an electric apparatus, such as a portable information terminal apparatus like a mobile telephone and PDA etc, car audio equipment, and a remote control unit for performing remote control operation. In particular, the invention relates to a multi-directional input key capable of plural inputs through multi-directional operation with a single input key.
2. Description of the Related Art
To meet a recent demand for an increase in the number of functions with which an electric apparatus is endowed, the input operation device of an electric apparatus as mentioned above is often equipped with a multi-directional input key capable of plural inputs through multi-directional operation with a single input key. As in the case of a mobile telephone, in a known multi-directional input key, an annular operation surface of an annular input key is depressed at one of four positions: top, bottom, right-hand, and left-hand positions, to thereby perform plural input operations. Then, in accordance with the respective inputs, scrolling of a display screen, selection of various items, movement of a cursor, etc is executed. In particular, in the mobile telephone, an incorporation of game applications is in vogue. To play with such game applications, plural inputs are usually effected by using an input key having the annular operation surface.
However, such a multi-directional input key as mentioned above involves a depressing operation in which force is applied from above so as to deeply push down the annular operation surface at one of the four positions: the top, bottom, right-hand, and left-hand positions. This operation often makes the operator feel fatigued at a relatively early stage. Thus, in addition to its rather small size, the input key has a problem in that its operability is not as satisfactory as it ought to be, which means the multi-directional input key leaves much to be desired before it can be used as the input operation device of an electric apparatus in which frequent use of the multi-directional input key is to be expected, e.g., a portable information terminal apparatus which allows utilization of electronic mail, game application or the like, as in the case of a mobile telephone or PDA.
The present invention has been made in view of the above problem in the prior art. It is an object of the present invention to provide a multi-directional input key for use as an input operation device for an electric apparatus in which it is possible to effect plural inputs through a novel multi-directional operation method instead of the conventional input operation method in which force is applied so as to deeply push the key.